Question

A body will weigh more in a vacuum than in the air. Justify the statement.

Answer 1

There is no denying the fact that a body will weigh more in a vacuum than in air. It can be explained below:

1. A body in the air experiences an upward thrust or buoyant force equal to the weight of the air that it displaces.
2. The buoyant force on the body acts opposite to the direction of the weight of the body.
3. Due to the buoyant force exerted on the body by the air, the body appears to be lighter.
4. Hence, when a body is weighed on a weighing machine, the weight of the body recorded will be less than the true weight of the body.
5. When a body is weighed in a vacuum, there occurs no reduction in the weight of the body because there is no fluid present in the vacuum that could exert a buoyant force on the body.
6. The weight of the body measured in the vacuum will be equal to the true weight of the body.

Hence, due to the absence of the buoyant force in a vacuum, a body will weigh more in a vacuum than in air.